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[Proceeding] Offloading Personal Security Applications to a Secure and
Trusted Network Node
Original Citation:
Bonafiglia R., Ciaccia F., Lioy A., Nemirovsky M., Risso F., Su T. Offloading Personal Security
Applications to a Secure and Trusted Network Node. In: First IEEE Conference on Network
Softwarization (Netsoft 2015), London, UK, 13-17 April 2015.
(In Press)
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IEEE
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Offloading personal security applications to a secure
and trusted network node
R. Bonafiglia§ , F. Ciaccia¶ , A. Lioy§ , M. Nemirovsky‡‡ , F. Risso§ , T. Su§
§ Politecnico
di Torino, Dip. Automatica e Informatica, Italy
Supercomputing Center (BSC), Spain
‡‡ ICREA Researcher Professor at Barcelona Supercomputing Center (BSC), Spain
¶ Barcelona
Abstract—The current device-centric protection model against
security threats has serious limitations from the final user
perspective, among the other the necessity to keep each device
updated with the latest security updates and the necessity to
replicate all the security polices across all devices. In our model,
the protection is decoupled from the users terminals and it is
provided through a Trusted Virtual Domain (TVD) instantiated
in future edge routers. Each TVD provides unified and homogeneous security for a single user, irrespective of the terminal
employed. This paper shows a first prototype implementing this
concept through a network element, called Network Edge Device,
capable of running the proposed virtualized architecture and
making extensive use of SDN technologies, with the aim at
providing a uniform security level for the final user.
I. I NTRODUCTION
Today’s classical approach to the security of personal devices requires the installation of security software directly on
the devices that need to be protected. With a growing number
of user terminals (laptops, smartphones, smart TVs, and more),
keeping all those devices protected has become a challenge;
achieving a uniform level of security across all of them would
be even harder. In fact, each device needs to be configured
with the proper security policies, while security patches (e.g.
related to the operating system and/or the installed software)
needs to be readily applied. However, this may not always be
possible, as some devices (e.g. smart TVs) may not support
the desired set of security properties, or security patches may
not be promptly released by the software manufacturer1 . The
above problems can be mitigated by processing all the network
traffic in a security device operating close to the user, possibly
integrated in an home gateway or an edge router. In a nutshell,
we propose to offload security to a personal Trusted Virtual
Domain (TVD) running in an Network Edge Device (NED), in
charge of executing all the user’s security applications on the
network traffic, regardless of the personal device in use, thus
reaching uniform network protection. This paper introduces
the main architectural components of the NED, followed by
a description of a prototype developed based on the above
architecture; finally a demonstration scenario of the prototype
is presented.
II. A RCHITECTURE
A. The TVD
The Trusted Virtual Domain is the main component of this
architecture: it is a logical container of all the user network
security. Each security control processes exclusively the traffic
of a single user, thus is called a Personal Security Application
(PSA). It runs in an Execution Environment (EE); the EE is a
placeholder for the PSA execution which should be adequately
separated from other users’ environment, guaranteeing traffic
isolation. Multiple PSAs for the same user can run in the
same EE in cascade. PSAs behaviour is monitored by another
component, the Personal Security Controller (PSC) which
is also in charge of configuring PSAs at startup time; the
PSC runs in a separate EE. The TVD is Trusted as all
the components (hardware and software) are being attested
following the principles of Trusted Computing [1]. In this way
is possible to verify that the software running on the NED is
not tampered according to some golden measurements.
B. The TVD Manager
The TVD Manager (TVDM) is the architecture Orchestration and Management component. Once the user is authenticated in the system, the TVDM deals with the requests to
instantiate a new TVD by determining the resources required
for its allocation and then commanding the deployment. The
TVDM performs an analysis of the required virtualization
technology and the management of the network topology
(physical and virtual) to support the deployment of the whole
user’s Service Graph (SG). The SG is the formalism that
describes the service requested by the user and it is, in its
simplest form, a set of cascaded PSAs active on the user’s
traffic. The SG is defined as the superposition of two directed
graphs in which nodes represent the PSAs and arcs represent
the flow of the traffic between two nodes. Arcs can be labelled
with a set of packet filtering rules (e.g. OpenFlow Flowmods)
that select which traffic has to flow through that arc in that
direction. The TVDM is in charge of translating this abstract
model into actual flow rules to be pushed in the virtual
switches, thus acting as an OpenFlow controller.
C. The PSC Manager
1 It
is worth mentioning that some versions of mainstream operating
systems, such as Android, Apple IOS or Microsoft Windows, are no longer
covered by the proper security patches, although their penetration in the
market is still far from marginal.
The PSC Manager (PSCM) is the front-end component of
the architecture; it includes the NED Authentication system
which can be implemented either locally or using an external
authentication infrastructure (AAA+, OAuth, OpenID...). The
PSCM grants an authentication token used by the rest of the
infrastructure components to identify the user.
D. Network topology
Users connect to the NED with a secure channel (it can
be an Ethernet cable, a WiFi encrypted channel or even
a remote encrypted connection, e.g. a VPN using IPsec).
Internally the NED presents two separate networks: the data
plane network and the control and management network. Their
means is to separate the user traffic (data plane) from the traffic
generated by the infrastructure components for management
and monitoring. The two networks are managed by two virtual
switches. The Data Plane switch forwards all the users’ traffic;
isolation of flows is guaranteed by fine-tuned rules in the
switch which allows for traffic steering towards, and only to,
the user’s TVD.
Fig. 1. A NED managing a multi-tenant scenario with different security
policies enforced
III. T HE PROTOTYPE
A pure software prototype of this architecture has been
developed in the context of the SECURED European project
[2]. The prototype relies on customized Virtual Machines
as Execution Environment for both PSAs and PSC. The
host is running a Fedora Linux distribution with the KVM
hypervisor together with QEMU. The NED software is running
on commodity hardware (x86 Intel CPU, 8GB RAM, 1Gbit/s
NIC with 2 ports). The development of the NED components
leveraged on fast prototyping tools (e.g. Python language) and
clean API interfaces (RESTful services). To conduct Remote
Attestation an external Third Party Verifier hosting the golden
measurements and attesting the NED trustability is needed.
The Verifier software has been developed and deployed on a
different machine using also the Python language. Functional
testing has been conducted on the prototype in a use case
scenario with two users connecting to the NED. Each user
connecting to the NED will go through these steps:
•
Trusted Channel establishment: a VPN tunnel using IPsec
is established towards the NED. The IPsec handshake is
not completed until the user terminal receives a trusted
verification report from the Verifier. This report proves
that the certificate used by the NED to create the secure
channel is controlled by the software actually in use, and
the software running in the NED is benign and in the
latest version.
•
User Authentication: the PSCM is now reachable and the
user can authenticate in the SECURED system.
•
TVD instantiation by TVDM: the authentication triggers
the TVD instantiation and configuration (PSC and PSAs
VMs are deployed).
Once the TVD is configured users are finally able to reach the
Internet taking advantage of the NED security controls (e.g.
in Fig. 1 user1 and user2 both have the firewall PSA but with
different policies enforced).
IV. C ONCLUSIONS AND FUTURE WORK
With the prototype implementation we demonstrated the
feasibility of the presented architecture. The system architecture, including also the external infrastructure architecture
[3], is easily mapped to an NFV deployment and a design
compatible with the ETSI standard [4] is currently under development. The concept of the Service Graph allows for complex
modeling of VNFs chaining, becoming an NFV enabler. The
security paradigm shift towards the network edge explores
the new possibility offered by Fog Computing, a scalable
architecture which will be an IoT key technology [5] [6].
Finally the Trusted Computing techniques here investigated
focus on the concepts of Remote Attestation, an ongoing
research topic which can provide authentic evidence about the
integrity status of the platform.
ACKNOWLEDGMENT
The research described in this paper is part of the SECURED project [2], co-funded by the European Commission
under the ICT theme of FP7 (grant agreement no. 611458).
R EFERENCES
[1] TCG infrastructure working group, “TCG architecture part ii: Integrity
management. tcg specification version 1.0, revision 1.0.”
[2] “Security at the network edge (SECURED),” http://www.secured-fp7.eu/.
[3] D. Montero, M. Yannuzzi, A. Shaw, L. Jacquin, A. Pastor et al.,
“Virtualized security at the network edge : A user-centric approach,” IEEE
Communications, to appear, 2015.
[4] ETSI
NFV
ISG,
“NFV
white
paper
ver.
2,”
https://portal.etsi.org/nfv/nfv white paper2.pdf, 2013.
[5] F. Bonomi, R. Milito, J. Zhu, and S. Addepalli, “Fog computing and its
role in the Internet of things,” in Workshop on Mobile Cloud Computing
(MCC), 2012, pp. 13–16.
[6] M. Yannuzzi, R. Milito, R. Serral-Gracia, D. Montero, and M. Nemirovsky, “Key ingredients in an IoT recipe: Fog computing, Cloud
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(CAMAD), 2014, pp. 325–329.